Double-coil oscillating motor



L. 0. CRENSHAW.

DOUBLE COIL OSCILLATING MOTOR.

APPLICATION FILED MAY 7, 19'9- 1,347,209, Patented July 20, 1920.

UNITED. STATES PATENT orrlcs.

LOREN o. GRENSHAW, OF ros ANGELES, CALIFORNIA, AssIGNon To MAGNETIC SIGNAL COMPANY, A CORPORATION or CALIFORNIA.

DOUBLE-COIL OSCILLATIQNG Moron.

To all whom it may concern:

Be it known that I, LOREN O. CRENsHAw, a citizen of the United States, residing at Los Angeles, county of Los Angeles, and State of California, have invented a new and useful Improvement in Signals Comprising a Double-Coil Oscillating Motor, of which the following is a specification.

M invention relates to signal devices and particularly to signals which are peculiarly adapted for use on railway crossings for the purpose of warning trafiic on the highway of the approach of trains along the railway. It may, of course, be used in other situations and for other purposes. I

In the form of my invention illustrated,

Figure 1 is a side elevation of my invention, the case being shown in section to better illustrate the invention.

Fig. 2 is a side view.

Fig. 3 is a diagram of connections."

In the form of my invention shown, a I

inthe top of which is secured a stationary armature 12 and in which is journaled a shaft 13. The shaft 13 extends through the side of the case 11 and carries a hub 14 on the upper end of which is secured a rod 15 carrying a display 16 and on the lower end of which is secured a rod 17 carrying a pendulum 18. Rigidly secured on the shaft 13 are two magnets 20 and 21 which have the form shown in Fig. 3 and which are spaced in relationship to the armature as shown in that figure. On the magnet 20 is an energizing coil 24 and on the magnet 21is an energizing coil 25; these coils being connected together at one terminal; their junction being connected through a wire 26 to contact making device 27 which is connected to one terminal of a battery 28 or other source of power. The other terminals of coils 24 and 25 are connected to moving contacts 30 and 31 which are carried on suitable insulation secured on the magnets 20 and 21 and making electrical contact with stationary contact fingers 32 and 33, these contact fingers being secured by common casting through a wire 36 to the other side of the battery 28. Contact 32 is rotated in clockwise direction by means of spring 40, the amount of this rotation being governed by set screws 41. The magnets 20 and case 11 is provided,

Specificationof Letters Patent.

21 are, so set with rela- Patented July 20, 1920.

Application filed May 7, 1919. Serial 110.295,?95.

tion to the shaft 13 that the magnet 20 is considerably nearer the armature 12 than the magnet 21 when the si nalis in its central position, as shown in Fig. 1.

Whenever the contact device is closed with the parts in the position shown in Fig. 1, which is the position the signal assumes when the current is cut off, both of the coils 24 and 25 are energized and both exert an attraction on the armature 12; the attraction of the magnet 20 is, however, due to its .nearerposition much greater than the attraction of the armature 21 and the shaft13 is therefore rotated in a clockwise direction, the magnet pulling in under the armature 12. This continues until the set screw 41 of contact finger 32 arrests its motion and opens the circuit between contact finger 32 and movable contact 30, thus deenergizing the coil 2 1-, the signal thereafter swinging by its own momentum through a considerable arc during which there is an attraction betweenvthe magnet 21 and the armature 12, although this attraction, due to the distance between the armature and the magnet is I quite small.

As, however, the signal swings back toward the central position, after having completed its arc of travel, this pull increases and continues until the signal swings slightly past its central position and the contact is broken vbetween the finger 33 and the contact 31. The alternate pull of the magnets 20 and 21 continues until the circuit is broken at the contact making device 27.

I claim as my invention: 1

I A double coil oscillating motor comprising a shaft; a pendulum dependent from said shaft; a magnet casting secured to said shaft and having two radial pairs of limbs both limbs of each radial pair being located in a radial plane to which said shaft is perpendicular, these planes being parallel to each other, the limbs in each radial plane being located in angular relationship toeach other but so disposed as to form, with one of the limbs in the other radial plane, an axial pair both of the limbs of each axial pair being the axis of said shaft, said axial planes forming a dihedral angle; an armature so located that it can come into magnetic relationship with each of said axial. pairs as said shaft is in a single axial plane which also contains rotated but being somewhat nearer one of said axial pairs than the other when said pendulum is in its lowest position; two coils each surrounding one of said limbs but heing located in different radial and axial planes; means for energizing both of said coils; and means for deenergizing each coil as the limb on which it is placed comes into its position of maximum magnetic pull. on said armature.

In testimony whereof, I have hereunto set myhand at Los Angeles, California, this 1st day of May, 1919.

LOREN O. CRENSHAW. 

